On the way to eternity believers are mere clay in the hands of the Heavenly Potter.
Philippians 1:6 Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ:
The activity of God in us, around us and for us makes our confidence in Him something that is precious, powerful and real.
God saved us to make us like Jesus, and He will keep working on us until that level of perfection has been achieved.
On that day this vile flesh with all its appetites and affections will be left behind forever, and we will be changed into His image and be with Him forever. That's why we sing, Blessed Assurance, Jesus is Mine.